Bundler [Prerelease]: Add force updater helpers

Adding Bundler v2 native helpers for the ForceUpdater.

bundler/helpers/v2/lib/functions.rb

@@ -3,8 +3,9 @@
 require "functions/conflicting_dependency_resolver"
 require "functions/dependency_source"
 require "functions/file_parser"
-require "functions/version_resolver"
+require "functions/force_updater"
 require "functions/lockfile_updater"
+require "functions/version_resolver"
 
 module Functions
   class NotImplementedError < StandardError; end
@@ -43,7 +44,15 @@ def self.update_lockfile(dir:, gemfile_name:, lockfile_name:, using_bundler2:,
   def self.force_update(dir:, dependency_name:, target_version:, gemfile_name:,
                         lockfile_name:, using_bundler2:, credentials:,
                         update_multiple_dependencies:)
-    raise NotImplementedError, "Bundler 2 adapter does not yet implement #{__method__}"
+    set_bundler_flags_and_credentials(dir: dir, credentials: credentials,
+                                      using_bundler2: using_bundler2)
+    ForceUpdater.new(
+      dependency_name: dependency_name,
+      target_version: target_version,
+      gemfile_name: gemfile_name,
+      lockfile_name: lockfile_name,
+      update_multiple_dependencies: update_multiple_dependencies
+    ).run
   end
 
   def self.dependency_source_type(gemfile_name:, dependency_name:, dir:,

bundler/helpers/v2/lib/functions/force_updater.rb

@@ -0,0 +1,167 @@
+module Functions
+  class ForceUpdater
+    class TransitiveDependencyError < StandardError; end
+
+    def initialize(dependency_name:, target_version:, gemfile_name:,
+                   lockfile_name:, update_multiple_dependencies:)
+      @dependency_name = dependency_name
+      @target_version = target_version
+      @gemfile_name = gemfile_name
+      @lockfile_name = lockfile_name
+      @update_multiple_dependencies = update_multiple_dependencies
+    end
+
+    def run
+      # Only allow upgrades. Otherwise it's unlikely that this
+      # resolution will be found by the FileUpdater
+      Bundler.settings.set_command_option(
+        "only_update_to_newer_versions",
+        true
+      )
+
+      dependencies_to_unlock = []
+
+      begin
+        definition = build_definition(dependencies_to_unlock: dependencies_to_unlock)
+        definition.resolve_remotely!
+        specs = definition.resolve
+        updates = [{ name: dependency_name }] +
+                  dependencies_to_unlock.map { |dep| { name: dep.name } }
+        specs = specs.map do |dep|
+          {
+            name: dep.name,
+            version: dep.version
+          }
+        end
+        [updates, specs]
+      rescue Bundler::VersionConflict => e
+        raise unless update_multiple_dependencies?
+
+        # TODO: Not sure this won't unlock way too many things...
+        new_dependencies_to_unlock =
+          new_dependencies_to_unlock_from(
+            error: e,
+            already_unlocked: dependencies_to_unlock
+          )
+
+        raise if new_dependencies_to_unlock.none?
+
+        dependencies_to_unlock += new_dependencies_to_unlock
+        retry
+      end
+    end
+
+    private
+
+    attr_reader :dependency_name, :target_version, :gemfile_name,
+                :lockfile_name, :credentials,
+                :update_multiple_dependencies
+    alias update_multiple_dependencies? update_multiple_dependencies
+
+    def new_dependencies_to_unlock_from(error:, already_unlocked:)
+      potentials_deps =
+        relevant_conflicts(error, already_unlocked).
+        flat_map(&:requirement_trees).
+        reject do |tree|
+          # If the final requirement wasn't specific, it can't be binding
+          next true if tree.last.requirement == Gem::Requirement.new(">= 0")
+
+          # If the conflict wasn't for the dependency we're updating then
+          # we don't have enough info to reject it
+          next false unless tree.last.name == dependency_name
+
+          # If the final requirement *was* for the dependency we're updating
+          # then we can ignore the tree if it permits the target version
+          tree.last.requirement.satisfied_by?(
+            Gem::Version.new(target_version)
+          )
+        end.map(&:first)
+
+      potentials_deps.
+        reject { |dep| already_unlocked.map(&:name).include?(dep.name) }.
+        reject { |dep| [dependency_name, "ruby\0"].include?(dep.name) }.
+        uniq
+    end
+
+    def relevant_conflicts(error, dependencies_being_unlocked)
+      names = [*dependencies_being_unlocked.map(&:name), dependency_name]
+
+      # For a conflict to be relevant to the updates we're making it must be
+      # 1) caused by a new requirement introduced by our unlocking, or
+      # 2) caused by an old requirement that prohibits the update.
+      # Hence, we look at the beginning and end of the requirement trees
+      error.cause.conflicts.values.
+        select do |conflict|
+          conflict.requirement_trees.any? do |t|
+            names.include?(t.last.name) || names.include?(t.first.name)
+          end
+        end
+    end
+
+    def build_definition(dependencies_to_unlock:)
+      gems_to_unlock = dependencies_to_unlock.map(&:name) + [dependency_name]
+      definition = Bundler::Definition.build(
+        gemfile_name,
+        lockfile_name,
+        gems: gems_to_unlock + subdependencies,
+        lock_shared_dependencies: true
+      )
+
+      # Remove the Gemfile / gemspec requirements on the gems we're
+      # unlocking (i.e., completely unlock them)
+      gems_to_unlock.each do |gem_name|
+        unlock_gem(definition: definition, gem_name: gem_name)
+      end
+
+      dep = definition.dependencies.
+            find { |d| d.name == dependency_name }
+
+      # If the dependency is not found in the Gemfile it means this is a
+      # transitive dependency that we can't force update.
+      raise TransitiveDependencyError unless dep
+
+      # Set the requirement for the gem we're forcing an update of
+      new_req = Gem::Requirement.create("= #{target_version}")
+      dep.instance_variable_set(:@requirement, new_req)
+      dep.source = nil if dep.source.is_a?(Bundler::Source::Git)
+
+      definition
+    end
+
+    def lockfile
+      return @lockfile if defined?(@lockfile)
+
+      @lockfile =
+        begin
+          return unless lockfile_name && File.exist?(lockfile_name)
+
+          File.read(lockfile_name)
+        end
+    end
+
+    def subdependencies
+      # If there's no lockfile we don't need to worry about
+      # subdependencies
+      return [] unless lockfile
+
+      all_deps =  Bundler::LockfileParser.new(lockfile).
+                  specs.map(&:name).map(&:to_s)
+      top_level = Bundler::Definition.
+                  build(gemfile_name, lockfile_name, {}).
+                  dependencies.map(&:name).map(&:to_s)
+
+      all_deps - top_level
+    end
+
+    def unlock_gem(definition:, gem_name:)
+      dep = definition.dependencies.find { |d| d.name == gem_name }
+      version = definition.locked_gems.specs.
+                find { |d| d.name == gem_name }.version
+
+      dep&.instance_variable_set(
+        :@requirement,
+        Gem::Requirement.create(">= #{version}")
+      )
+    end
+  end
+end

bundler/helpers/v2/spec/functions_spec.rb

@@ -5,8 +5,6 @@
 RSpec.describe Functions do
   # Verify v1 method signatures are exist, but raise as NYI
   {
-    force_update: [ :dir, :dependency_name, :target_version, :gemfile_name, :lockfile_name, :using_bundler2,
-                    :credentials, :update_multiple_dependencies ],
     private_registry_versions: [:gemfile_name, :dependency_name, :dir, :credentials ],
     jfrog_source: [:dir, :gemfile_name, :credentials, :using_bundler2],
     git_specs: [:dir, :gemfile_name, :credentials, :using_bundler2],

bundler/spec/dependabot/bundler/update_checker/force_updater_spec.rb

@@ -21,7 +21,7 @@
         "username" => "x-access-token",
         "password" => "token"
       }],
-      options: {}
+      options: { bundler_2_available: bundler_2_available? }
     )
   end
   let(:dependency_files) { [gemfile, lockfile] }
@@ -66,9 +66,9 @@
     subject(:updated_dependencies) { updater.updated_dependencies }
 
     context "when updating the dependency that requires the other" do
-      let(:gemfile_body) { fixture("ruby", "gemfiles", "version_conflict") }
+      let(:gemfile_body) { fixture("projects", "bundler1", "version_conflict", "Gemfile") }
       let(:lockfile_body) do
-        fixture("ruby", "lockfiles", "version_conflict.lock")
+        fixture("projects", "bundler1", "version_conflict", "Gemfile.lock")
       end
       let(:target_version) { "3.6.0" }
       let(:dependency_name) { "rspec-mocks" }
@@ -114,9 +114,9 @@
     end
 
     context "when updating the dependency that is required by the other" do
-      let(:gemfile_body) { fixture("ruby", "gemfiles", "version_conflict") }
+      let(:gemfile_body) { fixture("projects", "bundler1", "version_conflict", "Gemfile") }
       let(:lockfile_body) do
-        fixture("ruby", "lockfiles", "version_conflict.lock")
+        fixture("projects", "bundler1", "version_conflict", "Gemfile.lock")
       end
       let(:target_version) { "3.6.0" }
       let(:dependency_name) { "rspec-support" }
@@ -162,11 +162,9 @@
     end
 
     context "when two dependencies require the same subdependency" do
-      let(:gemfile_body) do
-        fixture("ruby", "gemfiles", "version_conflict_mutual_sub")
-      end
+      let(:gemfile_body) { fixture("projects", "bundler1", "version_conflict_mutual_sub", "Gemfile") }
       let(:lockfile_body) do
-        fixture("ruby", "lockfiles", "version_conflict_mutual_sub.lock")
+        fixture("projects", "bundler1", "version_conflict_mutual_sub", "Gemfile.lock")
       end
 
       let(:dependency_name) { "rspec-mocks" }
@@ -213,11 +211,9 @@
     end
 
     context "when another dependency would need to be downgraded" do
-      let(:gemfile_body) do
-        fixture("ruby", "gemfiles", "subdep_blocked_by_subdep")
-      end
+      let(:gemfile_body) { fixture("projects", "bundler1", "subdep_blocked_by_subdep", "Gemfile") }
       let(:lockfile_body) do
-        fixture("ruby", "lockfiles", "subdep_blocked_by_subdep.lock")
+        fixture("projects", "bundler1", "subdep_blocked_by_subdep", "Gemfile.lock")
       end
       let(:target_version) { "2.0.0" }
       let(:dependency_name) { "dummy-pkg-a" }
@@ -229,11 +225,9 @@
     end
 
     context "when the ruby version would need to change" do
-      let(:gemfile_body) do
-        fixture("ruby", "gemfiles", "legacy_ruby")
-      end
+      let(:gemfile_body) { fixture("projects", "bundler1", "legacy_ruby", "Gemfile") }
       let(:lockfile_body) do
-        fixture("ruby", "lockfiles", "legacy_ruby.lock")
+        fixture("projects", "bundler1", "legacy_ruby", "Gemfile.lock")
       end
       let(:target_version) { "2.0.5" }
       let(:dependency_name) { "public_suffix" }

bundler/spec/fixtures/projects/bundler1/version_conflict/Gemfile

@@ -0,0 +1,6 @@
+source "https://rubygems.org"
+
+gem "rspec-mocks", "3.5.0"
+gem "rspec-support", "3.5.0"
+
+gem "diff-lcs", "1.2.0"

bundler/spec/fixtures/projects/bundler1/version_conflict/Gemfile.lock

@@ -0,0 +1,19 @@
+GEM
+  remote: https://rubygems.org/
+  specs:
+    diff-lcs (1.2.0)
+    rspec-mocks (3.5.0)
+      diff-lcs (>= 1.2.0, < 2.0)
+      rspec-support (~> 3.5.0)
+    rspec-support (3.5.0)
+
+PLATFORMS
+  ruby
+
+DEPENDENCIES
+  diff-lcs (= 1.2.0)
+  rspec-mocks (= 3.5.0)
+  rspec-support (= 3.5.0)
+
+BUNDLED WITH
+   2.0.0.dev

bundler/spec/fixtures/projects/bundler1/version_conflict_mutual_sub/Gemfile

@@ -0,0 +1,4 @@
+source 'https://rubygems.org'
+
+gem 'rspec-expectations', '~> 3.5.0'
+gem 'rspec-mocks', '~> 3.5.0'

bundler/spec/fixtures/projects/bundler1/version_conflict_mutual_sub/Gemfile.lock

@@ -0,0 +1,21 @@
+GEM
+  remote: https://rubygems.org/
+  specs:
+    diff-lcs (1.3)
+    rspec-expectations (3.5.0)
+      diff-lcs (>= 1.2.0, < 2.0)
+      rspec-support (~> 3.5.0)
+    rspec-mocks (3.5.0)
+      diff-lcs (>= 1.2.0, < 2.0)
+      rspec-support (~> 3.5.0)
+    rspec-support (3.5.0)
+
+PLATFORMS
+  ruby
+
+DEPENDENCIES
+  rspec-expectations (~> 3.5.0)
+  rspec-mocks (~> 3.5.0)
+
+BUNDLED WITH
+   1.16.0